The move underlines how the controversial millionaire, who once described Mugabe as "100% decent and incorruptible", remains close to the government of Zimbabwe, where he is now said to be the biggest landowner.

Van Hoogstraten's chequered past includes four years behind bars after he paid a gang to attack a former business associate with a hand grenade. The judge described him as a "sort of self-imagined devil who thinks that he is an emissary of Beelzebub". He was also infamous as a slum landlord who acquired more than 2,000 properties during the 1980s housing boom and described his tenants as "filth".

The Zimbabwe government has a 37% shareholding. So if the two were combined it would give them 67%, a comfortable majority to make changes to the board, potentially including the removal of the chairperson, Farai Mutamangira.

Speaking from Brighton, East Sussex, van Hoogstraten, 69, told the Mail & Guardian that shareholders and workers are unhappy "over the long period of corruption and incompetent mismanagement at Hwange. Government has also been prejudiced, as the major shareholder."

The board members have committed a "criminal offence" by not calling for an extraordinary general meeting, he added, describing the current board's plan for a turnaround strategy as "too little too late".